ENH: Added functionality in resample to resolve #10530

Added tests for updated resample function

Changed if-statement to be lower-bound inclusive

Undid previous change to if statement

Fixed typo in resample.py

Fixed typo in _get_time_bins

Updated _resample_timestamp function

Updated condition in if-statement

Updated exceptions raised in resample

Moved test case into proper file

Fixed typo in test case

Updated tests for resampling fix

ENH: Updated code for fixing #10530

Removed extraneous print statements from tests

Moved code for fix to _get_time_delta_bins function

Updated tests for resample TimeDeltaIndex with base

Updated code for resample TimeDeltaIndex with base

Removed print statements from test case

Removed print statement in tests

Added note to what's new

Removed extra whitespace

Removed addtional whitespace

Removed whitespace

Removed whitespace in resample.py

Removed more whitespace in resample.py

Removed more whitespace

Fixed syntax in what's new

Author: captainsafia

doc/source/whatsnew/v0.17.0.txt

@@ -94,6 +94,8 @@ Other enhancements
 
 - Enable `read_hdf` to be used without specifying a key when the HDF file contains a single dataset (:issue:`10443`)
 
+- Added functionality to use ``base`` when resampling a ``TimeDeltaIndex`` (:issue:`10530`)
+
 - ``DatetimeIndex`` can be instantiated using strings contains ``NaT`` (:issue:`7599`)
 - The string parsing of ``to_datetime``, ``Timestamp`` and ``DatetimeIndex`` has been made consistent. (:issue:`7599`)
 

pandas/tseries/resample.py

@@ -238,6 +238,10 @@ def _get_time_delta_bins(self, ax):
         end_stamps = labels + 1
         bins = ax.searchsorted(end_stamps, side='left')
 
+        # Addresses GH #10530
+        if self.base > 0:
+            labels += type(self.freq)(self.base)
+
         return binner, bins, labels
 
     def _get_time_period_bins(self, ax):

pandas/tseries/tests/test_resample.py

@@ -11,6 +11,7 @@
 
 from pandas.core.groupby import DataError
 from pandas.tseries.index import date_range
+from pandas.tseries.tdi import timedelta_range
 from pandas.tseries.offsets import Minute, BDay
 from pandas.tseries.period import period_range, PeriodIndex, Period
 from pandas.tseries.resample import DatetimeIndex, TimeGrouper
@@ -627,6 +628,19 @@ def test_resample_base(self):
                              freq='5min')
         self.assertTrue(resampled.index.equals(exp_rng))
 
+    def test_resample_base_with_timedeltaindex(self):
+        rng = timedelta_range(start = '0s', periods = 25, freq = 's')
+        ts = Series(np.random.randn(len(rng)), index = rng)
+        
+        with_base = ts.resample('2s', base = 5)
+        without_base = ts.resample('2s')
+
+        exp_without_base = timedelta_range(start = '0s', end = '25s', freq = '2s')
+        exp_with_base = timedelta_range(start = '5s', end = '29s', freq = '2s')
+
+        self.assertTrue(without_base.index.equals(exp_without_base))
+        self.assertTrue(with_base.index.equals(exp_with_base))
+
     def test_resample_daily_anchored(self):
         rng = date_range('1/1/2000 0:00:00', periods=10000, freq='T')
         ts = Series(np.random.randn(len(rng)), index=rng)